Sperry: Fighting root rot with peat

Updated 6:38 pm, Friday, February 17, 2012

Q: How often do I need to apply sphagnum peat moss to my St. Augustine lawn to stop Take All Root Rot? It really seemed to help two years ago.

A: It's possible you would need to apply it every year. However, you can wait to monitor the situation. If the grass is yellowed and lethargic at the time it should normally be greening up and growing, you can apply the peat in April or May.

Q: Regarding mulching my plants, I applied cedar mulch around a few shrubs several years ago. Is it good "forever," or should I replace it occasionally? Do I need to pull it away from the plants, to keep fungus from growing? Also, could I use leaves from my trees and shrubs as a mulch?

A: Mulches are good as long as they are still recognizable. Once they decay enough that you can't identify what you started with, you need to be top-dressing with more mulch. You really don't need to rake and remove the old mulch unless it would make your landscape look a bit tidier. As for tree leaves, once they've been run though the mower, they're great as a short-term mulch, for example, around shrubs, perennials and vegetables.

Q: What is the best grass for heavy shade? Or, perhaps, a groundcover that could be mowed.

A: This is a question that appears here fairly frequently, albeit in slightly different wording each time. I try to answer it many of those times, since it's such a common problem for Texas gardeners. St. Augustine is our most shade-tolerant turfgrass, but it must have four to six hours of hot, direct summer sunlight to survive, more if you want it to grow vigorously. No groundcover replacement can tolerate regular mowing, and none is able to withstand pedestrian traffic. I've converted most of my shade-ravaged turf areas into mondograss (monkeygrass). While I don't mow it, at least it gives a nice, grasslike texture to its part of our landscape.

Q: Several months ago, I read about using cardboard and newspapers to keep my compost and garden free of weeds. I can't find that reference. What are your thoughts?

A: It's a great theory. However, it wouldn't be my choice. I prefer to use one of the roll-type mulches from the garden center (easier to cut and keep in place). Actually, even more often, I apply shredded tree leaves or finely ground pine bark mulch to my garden. The compost pile should keep itself weed-free if you're turning it often and if the pile is heating up because it's composting actively.

Mail questions to Neil Sperry, c/o Features, San Antonio Express-News, P.O. Box 2171, San Antonio, TX 78297-2171, or email him at SAENgardenQA@sperry gardens.com. For more of his advice, become a Neil Sperry fan on Facebook.